ok, the one thing that really should be removed isnt the counter-attack, but the disadvantage of a speed-attack, when you destroy his castle very fast now you will not get half as much money then when you take yar time, so being slow is overpowered atm
the difficulty is just that the computer can do things you cant, not that he is smarter or better upgraded. Cause i dont think i get a massive wave when they crash my castle till 50%